Alkoxy diaminostilbenedisulfonic acids



United States Patent ALKOXY DIAMINOSTILBENEDISULFONIC ACIDS Robert S.L0ng, Bound Brook, and Alice K. Kantor,

Plainfield, N. J., assignors to American Cyanamid Company, New York,N."Y., a corporation of Maine No Drawing. Original application October17, 1955,

Serial No. 541,074. Divided and this application November 29, 1956,Serial No. 624,989

4 Claims. (Cl. 260509) in which X is an alkoxy group and Y' is ahalogen. The new compounds of this invention are useful as intermediatesfor brighteners forcotton. V v

The use of optical bleaching agents to compensate for the naturalyellowing of fibers has become common in the art. These compounds absorbultra violet light and re-emit light in the blue range, thusautomatically compensating for the yellow of the fiber. Since morevisible light is' reflected than is incident upon the fiber, the clothactually appears to be whiter than ordinary white bleached cloth. Suchcompounds must have aflinity for the fiber and their fluorescence mustbe in the blue range. The additive efiect of yellow reflected light andblue fluorescence which results in an overall increase in totalreflected light'sh'a'rply differentiates this type of bleaching from thesubtractive eflect obtained when one uses the older type of bluing,which dyed the cloth a blue to compensate for the yellow.

\ such as those mentioned above.

ice

thus, the unsymmetrical compounds of our invention are prepared in thismanner.

The acylation of the intermediate diaminostilbene derivatives is carriedout by known methods using a variety of acylating agents. Among theacylating agents which may be used there can be cited benzoyl chlorideand its derivatives such as 2,4-dimethoxybenzoyl chloride, 2,4-die'thoxybenzoyl chloride, o-methoxybenzoyl chloride, 0- ethoxybenzoylchloride, 2,5dimethoxybenzoyl chloride, 2,5-diethoxybenzoyl chloride,p-methyl-o-methoxybenzoyl chloride, p-methoxybenzoyl chloride,p-benzoylaminobenzoyl chloride, and the like; other aromatic acidchlorides such as the naphthoyl chloride, diphenyl-4-carboxy chloride,and the like; triazine chlorides such as cyanuric chloride, andheterocyclic acid chlorides such as nicotinoyl chloride, picolinoylchloride, thenoyl chloride and similar acid chlorides. Since thetriazine residues are used in the brightener art to replace acyl groupsin brightener structures, the terms acyl must be interpreted to includethis type of radical. When a chloro triazine such as cyanuric chlorideis used, it can be condensed with either one or two mols of'the alkoxysubstituted diaminostilbene disulfonic acids or the diaminostilbenederivative-can be condensed with two cyanuric chlorides. In such cases,the other chlorines in the triazine nucleus can be replaced with avariety of groups such as hydroxyl, alkoxy, phenoxy, anilino,morpholino, bis-fl-hydroxy ethylamino, mono-B-hydroxy ethylamino, andthe like, in any combination desired. Any amino groups on stilbenemoieties which have not been acylated can be further acylated withbenzoyl chloride derivatives, or other agents best brightening eflect,all the free amino groups should be acylated in one way or another.

brighteners derived from the compoundsof our invention It is essentialin these compounds that the fluorescence be as much'as possible a trueblue. However, many brighteners are quite usable which fluoresce-eitherreddish or greenish shades of blue. Many brighteners have'been describedin the prior art as being derived from diaminostilbene disulfonic acid.Most of these fluoresce a reddish shade of blue. 'Brightenersderivedfrom chlorinated diaminostilbene disultonic acids have been described.Even these have a distinctly reddish shade of blue fluorescence. Thecompounds which are prepared from our invention, posses a greenish shadeof blue fluorescence, which had beenobtainable heretofore only withother, more expensive, intermediates. *It is most surprising that thereplacement of one chlorine in a dichlorodiaminostilbene disulfonic acidwith an alkoxy group Will give, an intermediate from which greenishshade brighteners can be obtained. One would not expect this change tohave such a marked eflect on the shade of fluorescence as to shift itfrom reddish blue to a greenish blue.

The brighteners prepared from the compounds of our invention are usefulin brightening cotton. They can be used by themselves or they can beusedin blends with redder shade brighteners to produce a neutral bluefluorescent eflect on the cloth.

' The compounds of our invention are prepared by forming thedichlorodinitrostilbene disulfonic acids by known methods and treatingthe same with a sodium alkoxide.

I techniques.

We have found that in such a preparation a most sur- I prisingphenomenon is observed. Even with a large excess of sodium alkoxide,only one of the chlorine atoms is replaceable by alkoxy under theconditions used, and

may be dyed on cotton using a bath containing soap solutions, orthey amybe applied by any of the usual laundry but have substantivity on viscoserayon. Under the proper conditions, that is, slightly acid baths,.thecompounds of our invention will also show substantivity to nylon and toanimal fibers, such as wool and silk.

It is an advantage of the brighteners derived from the intermediates ofour invention, that they have very similar substantivi ty on cotton tothat of the other diaminostilbene type brighteners. They are thereforevery compatible with such brighteners in the formation of blends of aneutral blue fluorescence.

This application is a division of our copending application, Serial No..541,074, filed October 17, 1955.

Our invention can be illustrated by the following examples in which theparts are by weight unless other-' wise specified. 7

' I Example 1 5 8.0311 HOaS air-Goa... N...

In order to obtain the They are primarily brighteners for cotton 3stilbene-2,2'-disulfonic acid, is isolated by filtration and dried.

Example 2 803B HOaS HzN CH=OH NH:

A mixture of 10 parts of Master Builders Iron Grade D, 100 parts ofwater and 0.5 part by volume of glacial acetic acid is heated to reflux.A solution of 2.5 parts ofS-methoxy-S-chloro-4,4'-dinitrostilbene-2,2-disulfonic acid disodiumsalt in 35 parts of Water is added to the mixture. The refluxing iscontinued until reduction is complete. The reaction mixture is then madealkaline by the addition of 2 parts of solid sodium carbonate. The ironsludge is separated by filtration and the filtrate acidified withconcentrated hydrochloric acid to give a strongly positive test on CongoRed indicator paper. The solution is reduced by boiling to one half ofits volume and then cooled in an ice bath. The product, 5- methoxy 5'chloro 4,4 diaminostilbene 2,2 disulfonic acid, is isolated byfiltration and dried.

Example 3 so H so H l E QCMF NH.

The procedure of Example 1 is followed using equiv-. alent amounts ofabsolute ethanol and sodium ethoxide in place of the methanol and sodiummethoxide. The solution of the starting material in absolute ethanol isboiled before adding the ethoxide to make certain all residual water inthe starting material is evaporated. The product is then reduced by theprocedure of Example 2.

Example 4 SI 3H HQ 0.1:0 aQNH.

CiHin C1 The procedure of Example 1 is followedusing equivalent amountsof butanol and sodium butoxide. The product is then reduced by theprocedure of Example 2.

Example 5 SOaNa NaOaS oHwQoonnQon=on CH3 CH3 1 After addition of 6 partsof sodium carbonate in parts of water, the pyridine is distilled offwith steam. To the remaining solution, 15 parts of salt is added and thereaction mixture cooled. The product, disodium- 4,4 bis (2,4dimethoxybenzamido) 5 methoxy- 5-chlorostilbene-2,2-disulfonate, isisolated by filtration and dried. The product obtained is soluble inwater and imparts to cotton a strong greenish blue fluorescence.

Similar products are obtained by starting with the products of Examples3 and 4 and following the above procedure.

Example 6 A stock solution of brightener is made by dissolving mg. ofbrightener in 5 liters of distilled water. Also, a stock soap solutionis prepared by dissolving 10 g. of soap powder in 2 liters of distilledwater.

Three one pint laundry jars are used for the test. To the first is added7.2 cc. of stock brightener solution, to the second is added 8.1 cc.,and to the last 9.0 cc. of stock brightener is added. Then to each jar,100 cc. of stock soap solution is added. Then distilled water is addeduntil the total volume is 150- cc. To each jar is added a 5 g. piece of80 x 80 cotton. The jars are then closed and placed in a Laundrometer atF. for 25 minutes. At the end of this time the jars are opened and thefabrics rinsed three times in cold water and then dried. The dyed fabricfrom each jar is then viewed under ultra violet light. It is found toappear quite White when compared with untreated cloth.

Example 7 When the intermediate of Example 2 is converted to abrightener by the method of Example 5 and dye tested by the method ofExample 6, the cotton'cloth fluoresces a greener shade of blue thancloth similarly dye tested using the brightener of the same structureexcept for presence of chlorine in place of the methoyl group in the 5position.

We claim:

1. Compounds which in their free acid form have the structure:

SOaH SOaH HzN CH=CH NH:

, in which X is chlorine and Y is lower alkoxy.

NHCO

No references cited.

1. COMPOUNDS WHICH IN THEIR FREE ACID FORM HAVE THE STRUCTURE: